Why is Frankfurt the frontrunner as international banks consider shifting certain functions out of London? Quite simply, it’s because so many firms already have full banking licenses in Germany.

The biggest headache for international banks hoping to move staff away from London to other EU states after the UK’s Brexit vote is securing a banking license. The whole process takes up to 9 months – 2-3 months to put an application together and a further six months for it to be approved.

It's fortunate, therefore, that most big U.S. banks already have full banking licenses in Germany. BaFin, the German finance regulator, has already issued full licenses to Citigroup, Goldman Sachs, J.P. Morgan and Morgan Stanley, along with Credit Suisse, UBS and Royal Bank of Scotland.

Our research shows that Goldman Sachs is also fully licensed in Paris, as is HSBC, while Barclays has a license in both France and Ireland.

J.P. Morgan has a full banking license in Dublin, as do Citi, Barclays and Wells Fargo.

The bank that's behind on its European banking licenses appears to be Bank of America Merrill Lynch, which doesn't have a full license anywhere in Europe but London - and only has a ‘designated activity company’ in Ireland.

It’s a lot easier to relocate staff from London if you already have a fully licensed subsidiary elsewhere in Europe. BaFin, the German regulator, tells us that it has not seen any additional applications from international banks since the UK’s Brexit vote.